Angiotensin peptide synthesis and cyclic nucleotide modulation in sympathetic stellate ganglia

Chronically elevated angiotensin II is a widely-establishedcontributor to hypertension and heart failure via its action on thekidneys and vasculature. It also augments the activity of peripheralsympathetic nerves through activation of presynaptic angiotensin IIreceptors, thus contributing to sympathetic over-activity. Although somecells can synthesis angiotensin II locally, it is not known if thismachinery is present in neurons closely coupled to the heart. Using acombination of RNA sequencing and quantitative real-time polymerase chainreaction, we demonstrate evidence for a renin-angiotensin synthesispathway within human and rat sympathetic stellate ganglia, wheresignificant alterations were observed in the spontaneously hypertensiverat stellate ganglia compared with Wistar stellates. We also used FörsterResonance Energy Transfer to demonstrate that administration ofangiotensin II and angiotensin 1-7 peptides significantly elevate cyclicguanosine monophosphate in the rat stellate ganglia. Whether the releaseof angiotensin peptides from the sympathetic stellate ganglia altersneurotransmission and / or exacerbates cardiac dysfunction in statesassociated with sympathetic over activity remains to be established.